Rover charging system

ABSTRACT

A charging system for an autonomous rover includes a charging interface with contacts that interface with the autonomous rover, a rover power source for the autonomous rover, and circuitry operated by the autonomous rover for controlling charging of the rover power source.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is continuation of U.S. patent application Ser. No.14/209,086, filed on Mar. 13, 2014, (now U.S. Pat. No. 11,565,598,) andclaims the benefit of U.S. Provisional Patent Application 61/798,282filed on Mar. 15, 2013, the disclosure of which is incorporated hereinby reference in its entirety. This application is also related to U.S.patent application Ser. No. 14/209,261, filed on Mar. 13, 2014.

BACKGROUND 1. Field

The exemplary embodiments generally relate to material handling systemsand, more particularly, to transport and storage of items within thematerial handling systems.

2. Brief Description of Related Developments

Generally the storage of items within, for example, a warehouse requiresa large building or storage structure space with an associatedfootprint. Automated vehicles, also referred to as autonomous rovers,may be used in these warehouses to place items in storage and removeitems from storage. The autonomous rovers may include energy storageunits that require charging before initial use and during use such aswhen recharging upon depletion.

It would be advantageous to have a charging system for charging anautonomous rover's energy storage unit. It would also be advantageous tocharge an autonomous rover's energy storage unit where the autonomousrover may be transferring material or wherever the autonomous rover maybe located.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and other features of the disclosed embodimentsare explained in the following description, taken in connection with theaccompanying drawings, wherein:

FIG. 1 is a schematic illustration of an automated storage and retrievalsystem in accordance with aspects of the disclosed embodiment;

FIG. 2 is a schematic illustration of an autonomous rover chargingsystem in accordance with aspects of the disclosed embodiment;

FIG. 3 is a schematic illustration of an exemplary charging station inaccordance with aspects of the disclosed embodiment;

FIGS. 4A-4C are schematic illustrations of an exemplary implementationof a charging system in accordance with aspects of the disclosedembodiment;

FIG. 5 is a schematic illustration of an exemplary implementation of acharging system in accordance with aspects of the disclosed embodiment;

FIG. 6 is a schematic illustration of an exemplary implementation of acharging system in accordance with aspects of the disclosed embodiment;

FIG. 7 is a schematic illustration of an exemplary implementation of acharging system in accordance with aspects of the disclosed embodiment;

FIGS. 8A and 8B are schematic illustrations of an exemplary set ofcharging pads in accordance with aspects of the disclosed embodiment;

FIG. 9 illustrates different charging modes for an autonomous rover inaccordance with aspects of the disclosed embodiment;

FIG. 10 is a schematic illustration of a control system for controllingan autonomous rover charging system in accordance with aspects of thedisclosed embodiment;

FIG. 11 is a schematic illustration of a system using a transportablecharger in accordance with aspects of the disclosed embodiment;

FIG. 12 is a schematic illustration of a system using a transportablecharger in accordance with aspects of the disclosed embodiment;

FIG. 13 is a schematic illustration of a charging system in accordancewith aspects of the disclosed embodiment;

FIG. 14 is a flow diagram in accordance with aspects of the disclosedembodiment; and

FIG. 15 is a flow diagram in accordance with aspects of the disclosedembodiment.

DETAILED DESCRIPTION

FIG. 1 schematically illustrates a storage and retrieval system inaccordance with an aspect of the disclosed embodiment. Although theaspects of the disclosed embodiment will be described with reference tothe drawings, it should be understood that the aspects of the disclosedembodiment can be embodied in many alternate forms. In addition, anysuitable size, shape or type of elements or materials could be used.

In accordance with aspects of the disclosed embodiment, the storage andretrieval system 100 may operate in a retail distribution center orwarehouse to, for example, fulfill orders received from retail storesfor case units such as those described in U.S. patent application Ser.No. 13/326,674 filed on Dec. 15, 2011, the disclosure of which isincorporated by reference herein in its entirety.

The storage and retrieval system 100 may include in-feed and out-feedtransfer stations 170, 160, input and output vertical lifts 150A, 150B(generally referred to as lifts 150), a storage structure 130, and anumber of autonomous rovers 110. The storage structure 130 may includemultiple levels of storage rack modules where each level includesrespective storage or picking aisles 130A, and transfer decks 130B fortransferring case units between any of the storage areas of the storagestructure 130 and any shelf of the lifts 150. In some aspects, a liftmay form a modular unit that may be part of, or an extension of, thetransfer deck. The storage aisles 130A, and transfer decks 130B are alsoconfigured to allow the autonomous rovers 110 to traverse the storageaisles 130A and transfer decks 130B for placing case units into pickingstock and to retrieve ordered case units.

The autonomous rovers 110 may be any suitable autonomous vehiclescapable of carrying and transferring case units throughout the storageand retrieval system 100. Suitable examples of rovers can be found in,for exemplary purposes only, U.S. patent application Ser. No. 13/326,674filed on Dec. 15, 2011; U.S. patent application Ser. No. 12/757,312filed on Apr. 9, 2010; U.S. patent application Ser. No. 13/326,423 filedon Dec. 15, 2011; U.S. patent application Ser. No. 13/326,447 filed onDec. 15, 2011; U.S. patent application Ser. No. 13/326,505 Dec. 15,2011; U.S. patent application Ser. No. 13/327,040 filed on Dec. 15,2011; U.S. patent application Ser. No. 13/326,952 filed on Dec. 15,2011; and U.S. patent application Ser. No. 13/326,993 filed on Dec. 15,2011, the disclosures of which are incorporated by reference herein intheir entireties. The autonomous rovers 110 may be configured to placecase units, such as the above described retail merchandise, into pickingstock in the one or more levels of the storage structure 130 and thenselectively retrieve ordered case units for shipping the ordered caseunits to, for example, a store or other suitable location.

The autonomous rovers 110 and other suitable features of the storage andretrieval system 100 may be controlled by, for example, one or morecentral system control computers, referred to as control server 120through, for example, any suitable network 180. The network 180 may be awired network, a wireless network or a combination of a wireless andwired network using any suitable type and/or number of communicationprotocols. In one aspect, the control server 120 may include acollection of substantially concurrently running programs that areconfigured to manage the storage and retrieval system 100 including, forexemplary purposes only, controlling, scheduling, and monitoring theactivities of all active system components, managing inventory andpickfaces, and interfacing with the warehouse management system 2500.The collection of substantially concurrently running programs may alsobe configured to manage an autonomous rover charging system and acharging system health monitoring function according to aspects of thedisclosed embodiment. The collection of substantially concurrentlyrunning programs may be referred to generally as system software.

The autonomous rovers 110 may require charging, for example, beforebeing placed into service, during operations, and/or after an extendedidle time. According to an aspect of the disclosed embodiment, thestorage and retrieval system 100 includes a charging system 130C forcharging power sources (see e.g. power sources 482, 522, 622, 722 inFIGS. 4A and 5-7 ) of autonomous rovers 110, 416, 516, 616, 716 at anysuitable time. Charging facilities may be located at any suitablelocation in the storage and retrieval system 100 such as, for example,at one or more of the input and output vertical lifts 150A, 150B, thelevels of storage rack modules, the storage or picking aisles 130A, thetransfer decks 130B, or at any point where material is transferred toand from the autonomous rovers 110 or any other suitable location of thestorage and retrieval system 100 where an autonomous rover may belocated.

FIG. 2 shows an exemplary block diagram of a charging system 200according to aspects of the disclosed embodiment. The charging system200 may be substantially similar to charging system 130C. The chargingsystem 200 generally includes an alternating current (AC) distributionsystem 210, at least one charging supply 220, and charging locations230.

The AC distribution system 210 may provide alternating current to one ormore charging supplies 220 and may be capable of supplying enough powerto enable all charging supplies 220 in the charging system 200 tooperate at full power simultaneously. The AC distribution system 210 mayinclude a main disconnect switch 212 and AC overload and short circuitprotection circuitry 214. An individual AC overload and short circuitprotection circuit may be provided for each charging supply 220 tofurnish fault isolation such that a failed charging supply will notaffect operation of other charging supplies. The alternating current maybe supplied at any suitable amperage or voltage level. For example, thecurrent may be supplied at 480, 400, 240, 230, 220, or 208 volts, 50 or60 Hz, in a three phase delta or Y configuration, at any appropriateamperage. While FIG. 2 shows a delta configuration and a four wire L1,L2, L3, protective earth (PE) connection, it should be understood thatthe aspects of the disclosed embodiments may utilize any suitableconfiguration such as, for example, a Y configuration with a neutralwire L1, L2, L3, N, PE connection. The alternating current may also besupplied to any suitable location within the storage and retrievalsystem 100.

The at least one charging supply 220 may include a communications port222, one or more charging modules 224, 226, and at least one set ofcontactors 228A, 228B. The communications port 222 may generally providecommunications between the control server 120 (FIG. 1 ) and the chargingsupply 220 through any suitable network, such as network 180, forenabling in service programming, control, and monitoring of the chargingmodules 224, 226 and contactors 228A, 228B. The communications port 222may operate to report any suitable information related to the chargingmodules 224, 226 such as, for example, an alarm state, enabled ordisabled status, status of contactors 228A, 228B, temperature, outputcurrent or voltage, voltage or current limits, and/or software version.

The communications port 222 may operate to receive commands such as, forexample, commands to enable and disable charging module output, switchcharging module output among constant current, constant voltage, orconstant power, change current and voltage limits, update software andcalibration data, and/or open or close contactors 228A, 228B. Thecommunications port 222 may also be enabled to report failures of thecharging modules 224, 226, for example, under voltage, over voltage,over current, over temperature, and no response.

The communications port 222 may be wired and/or wireless and may use anysuitable communication technology or protocol. According to an aspect ofthe disclosed embodiment, the communications port 222 may be a networkenabled power supply manager having an Internet Protocol (IP) address onthe network 180 (FIG. 1 ) and having a dedicated bus for communicationwith charging modules 224, 226.

While charging modules 224, 226 are capable of operating alone, twocharging modules may be grouped together in charging supply 220 toproduce a combined output. The combined outputs of charging modules 224,226, may be used to deliver power to one or more charging locations 230.As may be realized, while two charging locations 230 are illustrated inFIG. 2 with respect to charging modules 224, 226 it should be understoodthat any suitable number of charging modules 224, 226 may be connectedto power modules 224, 226 in any suitable manner. As may also berealized, each charging supply 220 may have any suitable number ofcharging modules 224, 226, 224A, 226A which may be combined to produce acombined output. For example, in one aspect charging modules 224, 226may have a combined output and charging modules 224A, 226A may have acombined output. In other aspects charging modules 224, 226, 224A, 226Amay have a combined output while in still other aspects any two or moreof the charging modules 224, 226, 224A, 226A may be combined in anysuitable manner to provide a combined output. Each charging location 230may have a dedicated contactor 228A, 228B. Charging modules 224, 226(and the other charging modules described herein), may be configuredsuch that upon failure of one charging module 224, 226, the othercharging module 224, 226 may be capable of delivering current to the oneor more charging locations 230. According to some aspects, the remainingcharging module 224, 226 may deliver a reduced amount of current to thecharging locations 230. In one aspect, the charging supply 220 (and theother charging supplies described herein) may be controlled in anysuitable manner such that power output by the charging supply 220 may beallocated to respective charging locations 230 depending on a level ofcharge of the autonomous rovers 110 engaged at each charging location.For example, also referring to FIGS. 13 and 14 charging locations 230A,230B, 230C may be connected to charging supply 220 and a rover 110A,110B, 110C may be provided or otherwise located at a respective charginglocation 230A, 230B, 230C (FIG. 14 , Block 1400). For exemplary purposesonly, rover 110A may have the lowest charge level of the rovers 110A,110B, 110C. Rover 110C may have the highest charge level and rover 110Bmay have a charge level between the charge levels of rovers 110A and110C. In one aspect all or most (or any other suitable portion of) thepower output from the charging supply 220 may be allocated to anautonomous rover having the least amount of charge (e.g. such as rover110A) (FIG. 14 , Block 1401) up to the point where the charge of thatautonomous rover 110A is substantially equal to a charge of another ofthe autonomous rovers (e.g. such as rover 110B having the next leastamount of charge) at one of the respective charging locations (FIG. 14 ,Block 1402). Once the charge level of rover 110A is substantially thesame as the charge level of rover 110B, autonomous rovers 110A and 110Bmay receive all or most (or any other suitable portion of) the poweroutput from charging supply 220 (FIG. 14 , Block 1401) until theircharge is substantially equal to a charge of another autonomous rover(e.g. having the next least amount of charge such as rover 110C) at oneof the respective charging locations (FIG. 14 , Block 1402) and so on(e.g. continue with loop of FIG. 14 , Blocks 1401, 1402) until thecharging of the rovers is complete (FIG. 14 , Block 1403). If all therovers 110A, 110B, 110C at the charging locations 230A, 230B, 230C aresubstantially the same (e.g. have substantially the same level ofcharge) the power supply 220 may direct power to each of the rovers110A, 110B, 110C until charging is complete (FIG. 14 , Block 1403) oruntil some other predetermined criteria is met (e.g. a predeterminedcharge percentage of the rover, a command for a rover to leave thecharging location, or any other suitable criteria).

Each charging module 224, 226 (and the other charging modules describedherein) may be “hot pluggable” meaning that each charging module 224,226 may be replaceable without power cycling the charging module 224,226 being replaced and/or without power cycling the charging supply inwhich the charging module 224, 226 is located. The “hot pluggable”replacement of the charging module 224, 226 may be done withoutaffecting the operation of any other charging modules and while thecharging locations 230 are active. Each charging module 224, 226 may becapable of switching between a constant current, constant voltage, orconstant power output mode (FIG. 15 , Block 1504). In one aspectswitching between different output modes may be controlled in anysuitable manner such as by commands received from communications port222. In another aspect switching between different output modes may beaffected automatically by the charging module. In still other aspectsswitching between different output modes may be controlled by a rover110 and/or the control server 120 (FIG. 15 , Block 1505).

The charging system 200 may include any number of charging supplies 220.A charging supply 220 may include any number of charging modules 224,226 and may be capable of supplying any number of charging locations 230on any number of storage levels. For example, a charging supply 220 mayinclude two charging modules 224, 226 and may provide power to fourcharging locations 230 where two charging locations are disposed on eachof two levels served by a vertical lift 150A or 150B. For example,referring to FIG. 2 , charging locations 230A, 230B may be located onlevel 130L1 of the storage structure 130 while charging locations 230B,230C may be located on level 130L2 of the storage structure 130.

The charging modules 224, 226 may be configured with outputs that areenabled when an autonomous rover 110 both accesses and de-accessescharging contacts 816, 818 of a charging pad 810 (FIG. 8A) located at arespective charging location 230 (e.g. where the charging contacts 816,188 are connected to the charging modules 224, 226) to maximize acharging duty cycle and minimize charging delays (FIG. 15 , Block 1500).The charging supply 220 may have several different operating modesincluding, for example, an operating mode where all contactors 228A,228B are disabled, an operating mode where all contactors 228A, 228B areenabled, and/or an operating mode where a single or more than onecontactor 228A, 228B is disabled. Upon power up, the charging supply 220may initialize with contactors 228A, 228B disabled and open. Thecommunication port 222 may enable the contactors 228A, 228B afterreceiving a command from a charging system health monitoring functionsystem software, or for example, control server 120. Each contactor228A, 228B may have an auxiliary contact 229A, 229B, respectively whichmay be monitored to determine the state of the respective contactor228A, 228B. During normal operations, the contactors 228A, 228B may beclosed, energizing the charging pads 810 at the charging locations 230.The closed state of the contactors 228A, 228B may be verified bymonitoring the auxiliary contacts 229A, 229B. For maintenance access, asingle contactor, e.g. 228A or 228B may be disabled so that no currentflows through the associated charging location 230. This may be verifiedin any suitable manner such as by monitoring auxiliary contact 229A,229B. As may be realized, and as noted above, each charging supply mayhave any suitable number of contactors 228A, 228B connected to anysuitable number of charging locations 230 such that any one or more ofthe contactors 228A, 228B may be disabled for providing maintenanceaccess to any suitable number of charging locations 230.

According to some aspects, charging modules 224, 226 may be configuredto charge any suitable power source, such as power sources 482, 522,622, 722 (FIGS. 4A and 5-7 ) disposed on an autonomous rover including abattery pack and/or a capacitor based power source such as, for example,an ultracapacitor bank including one or more ultracapacitors (FIG. 15 ,Block 1501). It is noted that the power sources 482, 522, 622, 722 areillustrated as ultracapacitors but in other aspects the power sourcesmay be any suitable power sources.

FIG. 3 shows a schematic illustration of an exemplary charging station300 in accordance with aspects of the disclosed embodiment. The chargingstation 300 may be disposed at any suitable location of the storage andretrieval system 100. In one aspect the charging station 300 may includean internal power supply 305, a communications port 310, two chargingsupplies 315, 320, and four contactors 332, 334, 336, 338, eachproviding charging facilities to charging pads 810 (FIG. 8A) disposed atcharging locations which may be located at different levels 352, 354,356, 358, respectively, of the storage structure 130. In other aspectsthe charging station 300 may have any suitable configuration.

In this exemplary aspect, communications port 310 may be implemented asa dual Ethernet gateway (e.g. having two Ethernet gateways 340, 342)with at least one power supply management bus 344, 346 capable ofcontrolling one or more charging modules 360, 362, 364, 366. EachEthernet gateway 340, 342 may have any suitable configuration andinclude a media access control (MAC) address chip and an assigned IPaddress on network 180 (FIG. 1 ). As a result, each charging supply 315,320 may have an Ethernet address or be identified on network 180 in anysuitable manner. In one aspect there may be two power supply managementbusses 344, 346 (in other aspects any suitable number of power supplymanagement busses may be provided) that may conform, for example, to thePower Management Bus (PMBus) standard. Each power supply management bus344, 346 may control any suitable number of charging modules 360, 362,364, 366. In this example, power supply management bus 344 may beconnected to charging modules 360, 362 and power supply management bus346 may be connected to charging modules 364, 366.

Each charging supply 315, 320 may be substantially similar to thatdescribed above and include one or more charging modules 360, 362, 364,366, grouped together, for example, in pairs, with each pair providing ashared output. In other aspects the one or more charging modules may begrouped together in any suitable manner. Each charging module 360, 362,364, 366 may be hot pluggable as described above, and may be capable ofswitching between a constant current, constant voltage, or constantpower output mode, as described above and as controlled by commands fromcommunications port 310, affected automatically by each charging module,controlled by a rover 110, or controlled by the control server 120.

FIG. 4A is a schematic illustration of an exemplary implementation of acharging system 400 for charging the rover power source 482 inaccordance with aspects of the disclosed embodiment. Charging system 400includes an AC distribution system 210, one or more charging stations410, an intermediate DC bus 412, and a charging interface 414 connectedto a charging pad 450 with contacts 816, 818 (similar to charging pad810 in FIG. 8A) that interface with an autonomous rover 416 (which maybe substantially similar to rover 110 described above). The charginginterface 414 may include, for example, a floor mounted charging pad 450with charging contacts 816, 818 (FIG. 8A) and a rover mounted chargingpad 452 (similar to charging pad 820 in FIG. 8A). The charging pads 450,452 may interface or engage each other in any suitable manner such asthat described below with respect to FIGS. 8A and 8B. In some aspects,the voltage present on the intermediate DC bus 412, and hence thevoltage present on the charging contacts 816, 818, may be consideredextra low voltage and may require less protection, or in some aspects,no protection, against electrical shock.

Charging stations 410 may include any suitable number of chargingmodules 440, 442 (which may be substantially similar to those chargingmodules described above), generally configured in groups of two (or ingroups of any suitable number of charging modules) with combined outputsfor delivering charging power to one or more autonomous rovers 416. Agroup of any number of charging modules with combined outputs fordelivering power may be referred to as a charging supply (see e.g.charging supplies 220, 315, 320 described above).

The rover 416 may include what may be referred to as “hot swap”circuitry 418 or other suitable protection circuitry configured to allowthe rover 416 to connect to an energized or otherwise enabled chargingpad 450 (e.g. “hot swap” refers to the autonomous rover's ability tomake and break contact, such as contact between the charging padcontacts 816, 818 and the rover charging contacts 826, 828 of charginginterface 414, while the charging pads 450 are energized—see FIGS. 8Aand 8B). As shown in FIG. 4B, the hot swap circuitry 418 may includecurrent inrush limitation circuitry 422, reversal protection circuitry424, and charging control circuitry 426. The current inrush limitation,charging control, and reversal protection circuitry may be implementedin any suitable manner such as, for example, under control of anautonomous rover controller 420. The reversal protection circuitry 424may also be implemented, for example, using one or more Field EffectTransistors (FET's) or in any other suitable manner. The autonomousrover controller 420 may provide commands to the hot swap circuitry 418,for example, to set current inrush limits and/or enable or disable rovercharging. As a result, whether charging of the rover is on or off iscontrolled locally on the rover 416 so that no control loop with thecharging station 410 or the control server 120 is required (e.g.enabling or disabling charging of a rover is controlled by the rover 416independent of the charging station 410 and control server 120) (FIG. 15, Block 1506).

As shown in FIG. 4C, the autonomous rover controller 420 may include aprocessor 430, a memory 432, and a communications interface 434. Thecommunications interface 434 may generally provide communicationsbetween the control server 120 (FIG. 1 ) and the autonomous rover 416 atleast for controlling rover operations, providing information aboutcharging supplies and charging modules, and/or controlling chargingsupply and charging module operations.

It should be noted that each charging module 440, 442 in charging system400 may be configured to switch between a constant current, constantvoltage, and/or constant power output mode in a manner substantiallysimilar to that described above. As also noted above, in one aspectswitching between different output modes may be controlled in anysuitable manner such as by commands received from communications port222. In another aspect switching between different output modes may beaffected automatically by the charging module. In still other aspectsswitching between different output modes may be controlled by a rover110 and/or the control server 120.

It should also be noted that the autonomous rover 110, 416 entry to acharging location 230 that, for example includes, charging interface414, is decoupled or independent from a status of the charging station410, a status of the charging location and/or a status of the charginginterface 414 (FIG. 15 , Block 1502). The autonomous rover controller420 may control the hot swap circuitry 418 and the output of chargingstation 410 to effect charging of the autonomous rover power source,regardless or otherwise independent of the charging station 410 status,charging location 230 status or charging interface 414 status beforeand/or after contact is made (e.g. when the rover 110, 416 accesses andde-accesses the charging interface 414) between charging contacts 816,818 (FIG. 8A) of the rover 110, 416 and charging contacts 826, 828 (FIG.8B) of the charging interface 414. In at least one aspect of thedisclosed embodiment, an output of a charging supply, such as chargingsupply 220, 315, 320, is enabled when the rover 110, 416 accesses andde-accesses the charging contacts 826, 828 of the charging pad 450 ofthe charging interface 414 (FIG. 15 , Block 1503). The autonomous rovercontroller 420 may also control the output of charging station 410 tochange a state of the charging interface 414 between safe and unsafe(e.g. un-energized and energized, respectively) to effect a hot swapentry and departure of the autonomous rover 110, 416 with respect to acharging location 230.

As mentioned above, charging locations 230 may be located at anysuitable location in the storage and retrieval system 100 where materialis transferred to and from the autonomous rover 110 or at any othersuitable location at which the autonomous rover 110 may be disposed. Itshould be understood that autonomous rover charging may be accomplishedwhile an autonomous rover 110 is transferring material to and from theautonomous rover 110. It should also be understood that the rover entryto a material transfer location, such as at lift 150A, 150B location, ina picking aisle or any other suitable transfer location, withsimultaneous charging under rover control is independent ofcommunication between the control server 120 and the rover communicationinterface 434 (e.g. independent of the control server commands). Itshould further be understood that an autonomous rover 110 does not needclearance from the control server 120 or any other system component toeffect a charging operation, or for entry onto a charging pad, as longas entry to the charging pad is not blocked, for example, by anotherrover.

FIG. 5 shows a schematic illustration of another exemplaryimplementation of a charging system 500 in accordance with aspects ofthe disclosed embodiment. Charging system 500 includes AC distributionsystem 210, at least one DC power supply 510, an intermediate DC bus512, and at least one charging interface 514 (substantially similar tothat described above) with a charging pad 550 (that is substantiallysimilar to charging pad 450 described above) having contacts 816, 818(FIG. 8A) that interface with an autonomous rover 516 (that issubstantially similar to rovers 110, 416 described above). The charginginterface 514 may include, for example, the floor mounted charging pad550 and a rover mounted charging pad 552 (substantially similar to rovermounted charging pad 452 described above).

According to some aspects, the autonomous rover 516 may include hot swapcircuitry 518 (substantially similar to that described above) and acharging supply 520 for charging a power source 522. According to otheraspects, the voltage present on the intermediate DC bus 512 may beconsidered high voltage and all components used in the intermediate DCbus and connected to the voltage of the DC bus, or components that maybe connected to the DC bus voltage in a single fault case, must be madefinger safe, for example, protected against finger contact or solidforeign bodies, typically using an insulating barrier having an openingof 12 mm or less. In some aspects this may include the charging pads 550where the charging pads are configured in any suitable manner to befinger safe.

The hot swap circuitry 518 may include current inrush limitationcircuitry 524, reversal protection circuitry 526, and charging controlcircuitry 528, similar to hot swap circuitry 418 (FIG. 4 ). The hot swapcircuitry 518 may be under control of the autonomous rover controller530. According to some aspects, the autonomous rover 516 includes arover charging supply 520. The rover charging supply 520 may be similarto charging supply 220, and may be capable of switching between aconstant current, constant voltage, or constant power output mode.Switching of the charging supply 520 between different output modes maybe controlled by commands received from the autonomous rover controller530, may be affected automatically by the rover charging supply 520,and/or may be controlled by the control server 120. In at least oneaspect of the disclosed embodiment, an output of the charging supply 520is enabled when the rover accesses and de-accesses the charging contactsin a manner substantially similar to that described above.

FIG. 6 shows a schematic illustration of another exemplaryimplementation of a charging system 600 in accordance with aspects ofthe disclosed embodiment. Charging system 600 includes AC distributionsystem 210, an intermediate AC bus 612, and at least one charginginterface 614 (that may be substantially similar to those describedabove) with a charging pad 650 (substantially similar to that describedabove) having any suitable number of contacts substantially similar tocontacts 816, 818 (FIG. 8A) that interface with an autonomous rover 616(which may be substantially similar to those described above). Thecharging interface 614 may include, for example, the floor mountedcharging pad 650 and a rover mounted charging pad 652 (substantiallysimilar to the rover mounted charging pads described above). Similar tothe aspects shown in FIG. 5 , the voltage present on the intermediate ACbus 612 may be considered high voltage and all components used in theintermediate AC bus and connected to the voltage of the AC bus, orcomponents that may be connected to the AC bus voltage in a single faultcase, must be made finger safe.

According to some aspects, the number of contacts in charging interface614 may be determined by the type of AC power provided by theintermediate AC bus 612. For example, a delta configuration with fourwire L1, L2, L3, and PE connections may have three contacts as shown inFIG. 6 , or a Y configuration with neutral wire L1, L2, L3, N, and PEconnections may have four contacts.

According to other aspects, the autonomous rover 616 may includerectifier and hot swap circuitry 618 and a charging supply 620 forcharging a power source 622. The rectifier and hot swap circuitry 618may include circuitry 624 for rectification of power received from theintermediate AC bus 612, current inrush limitation circuitry 626,reversal protection circuitry 628, and charging control circuitry 630.

The rectifier and hot swap circuitry 618 may operate under control ofthe autonomous rover controller 632 or in any other suitable manner.Similar to the aspects shown in FIG. 5 , the autonomous rover 616includes a rover charging supply 620 (that may be substantially similarto those described above), which may be capable of switching between aconstant current, constant voltage, and/or constant power output mode ascontrolled by the autonomous rover controller 632 and/or the controlserver 120. In at least one aspect of the disclosed embodiment, anoutput of the charging supply 620 is enabled when the rover accesses andde-accesses the charging contacts of the charging pad 650 in a mannersubstantially similar to that described above.

Another exemplary implementation of a charging system 700 in accordancewith aspects of the disclosed embodiment is shown in FIG. 7 . Thisexemplary charging system 700 includes AC distribution system 210, atleast one DC power supply 710, an intermediate DC bus 712, hot swapcircuitry 714, and at least one charging interface 718 (that may besubstantially similar to those described above) with a charging pad 750having contacts 816, 818 (FIG. 8A) that interface with an autonomousrover 716 (which may be substantially similar to those described above).The charging interface 718 may include, for example, the floor mountedcharging pad 750 and a rover mounted charging pad 752 (that may besubstantially similar to those described above).

The DC power supply 710 may be substantially similar to those describedabove and may be capable of switching between a constant current,constant voltage, and/or constant power output mode in a manner similarto that described above. In a manner similar to that described above,switching between different output modes may be affected automatically,may be controlled by commands received from a controller of theautonomous rover 716, and/or may be controlled by the control server120. In some aspects of the disclosed embodiment, an output of the DCpower supply 710 is enabled when the rover 716 accesses and de-accessesthe charging contacts of the charging pad 750 in a manner substantiallysimilar to that described above.

According to some aspects, the voltage present on the intermediate DCbus 712 may be considered high voltage and all components used in theintermediate DC bus and connected to the voltage of the DC bus, orcomponents that may be connected to the DC bus voltage in a single faultcase, must be made finger safe. In other aspects, the voltage present onthe intermediate DC bus 712 may be considered extra low voltage and mayrequire less protection against shock.

Exemplary aspects of components of the charging interface 414, 514, 614,718 are shown in FIGS. 8A and 8B. FIG. 8A shows an example of a floormounted charging pad 810. The floor mounted charging pad 810 may includea base 812 which may be mounted on a floor of the storage structure 130or wherever a charging location 230 may be located. A movable cover 814may be provided which may be biased in the direction of arrow 899A in aclosed position, such that the movable cover 814 is disposed over thecontacts 816, 818 of the charging pad 810. In other aspects, a cover maynot be provided on the charging pad 810. According to some aspects,contact 816, which may be connected to a negative DC voltage of arespective power supply, may have a longer length than contact 818,which may be connected to a positive DC voltage of a respective powersupply, in order to facilitate the negative contact 816 being engagedboth first and last as the rover drives on and off the charging pad 810.An exemplary rover mounted charging pad 820 is shown in FIG. 8B. Therover mounted charging pad 820 may include rover charging contacts 826,828 mounted, for example, on an underside 830 of the rover mountedcharging pad 820. The rover mounted charging pad 820 may be mounted, forexample, to an underside of an autonomous rover for establishing amating relationship with the floor mounted charging pad 810. In someaspects, the rover mounted charging pad 820 may be mounted with a coverpusher 822 or other suitable member for moving the cover 814 in thedirection 899B as the rover moves relative to the floor mounted chargingpad 810 to expose contacts 816, 818 of the floor mounted charging pad810 for effecting an electrical connection between the charging pads810, 820. In other aspects, a cover pusher may not be provided. As maybe realized, when the rover disengages the floor mounted charging pad,relative movement between the rover (e.g. the cover pusher 822) and thefloor mounted charging pad 810 may allow the biasing force on the cover841 to move the cover 841 in the direction of arrow 899A so that thecontacts 816, 818 are covered. In still other aspects, hot swapcircuitry 418, 518, or rectifier and hot swap circuitry 618 may bemounted on a top side 824 of the rover mounted charging pad 820.

As mentioned above, an autonomous rover controller 420, 530, 632, maycontrol charging of its onboard power source and/or each of the chargingmodules within each charging supply. According to some aspects, theautonomous rover controller 420, 530, 632, may be configured to effectdifferent charging modes for the autonomous rover power sources describeabove such as, for example, power sources 482, 522, 622, 722. It shouldbe understood that the specified voltage and current levels describedare exemplary and may vary, for example, according to the state of thepower source being charged and the time available for charging. Thecharging modes may include a pre-charge mode, a force charge mode,charge enabled and disabled modes, full, quick, and incomplete chargemodes, and a trickle charge mode. According to some aspects, all modesexcept the pre-charge mode may require that the autonomous rovercontroller 420, 530, 632 be active.

It should also be understood that when more than one autonomous rover isbeing charged simultaneously (as described above), in some aspects, allor most of the current may be supplied to the rover with the lowestpower source voltage until the power source voltage rises to that of arover having a next lowest power source voltage, at which point currentwill be shared between the charging rovers.

The pre-charge mode is used for a fully depleted power source, forexample, after shipping with shorted power source terminals. Thepre-charge mode may provide a constant current at, for example, anysuitable amperage such as approximately 5 A while the power sourcevoltage increases from approximately 0V to any suitable predeterminedvoltage such as approximately 18V.

The force charge mode may be activated if the output of the power sourceexceeds any suitable voltage such as, for example, approximately 14V. Inthe force charge mode, charging may be activated at any suitableconstant full current such as, for example, approximately 110 A or anyother suitable current.

A charge disabled mode may be activated when the rover power sourcevoltage is within normal operating limits and the autonomous rovercontroller determines that no charge is required. In other aspects, thecharge disabled mode may be activated at any suitable time.

A charge enabled mode may be activated when the rover power sourcevoltage is within normal operating limits and charging is required asdetermined by the autonomous rover controller. In other aspects, thecharge enabled mode may be activated at any suitable time.

The autonomous rover controller may activate a full charge mode at aconstant voltage in order to fully charge the rover power source to apredetermined value such as, for example, to approximately 99.3% (toaccount for power source voltage minus diode drop) of a predeterminedfull charge value. In other aspects, the full charge mode may beactivated at any suitable time.

A quick charge mode may be activated where a constant current charge isfollowed by a constant voltage charge but charging is terminated beforea full charge state is complete. This mode may provide a sufficientcharge level to allow the rover to complete at least one task assignedto the rover. The quick charge mode may be activated at any suitabletime.

The autonomous rover controller may activate an incomplete charge modewhen a rover is only required to complete a predetermined assigned task.In this mode charging may be terminated before completion, as soon arequired energy level to perform the assigned task is achieved. Theavailable energy for the assigned task may be estimated from the chargevoltage or determined in any other suitable manner.

The autonomous rover controller may also activate, at any suitable time,a trickle charge mode where the rover power supply is charged with arelatively low current over an extended period of time.

FIG. 9 shows an exemplary progression among different charging modes.Referring to item 910, if the rover power source voltage is less thanany suitable predetermined threshold, for example, approximately 14-18V,the voltage of the charging supply may be detected in any suitablemanner such as by the a sensor or meter in the charging supply, bycontrol server 120 and/or by the rover controller as shown in item 912.If the voltage of the charging supply exceeds any suitable predeterminedvoltage such as, for example, 30V, the rover may enter the pre-chargemode 914 which provides, for example, any suitable constant current suchas, for example, approximately 5 A between any suitable voltage levelssuch as approximately, 0V and 18V. Pre-charging mode may end when therover power source reaches a predetermined voltage such as, for example,approximately 18V, or if a force charge mode is activated, as shown initem 916.

The force charge mode 916 may be activated upon the output of the powersource reaching a suitable voltage such as, for example, approximately14V-18V during the pre-charge mode. In the force charge mode, chargingmay be activated at for example, full current, or any suitable currentsuch as approximately 110 A. The force charge mode 916 may be terminatedafter the rover software is operational, as shown in item 918, and a bitis set in a register in the autonomous rover controller, shown as item922 and as explained below.

When the rover software is operational and the power source voltage iswithin normal operating limits (for example, approximately 25V to 46.3Vor any other suitable voltage range), charging may be disabled under thecontrol of the software running on the rover by setting a bit in acomplex programmable logic device (CPLD) register in the autonomousrover controller or in any other suitable location of the controller, asshown in item 922. As shown in item 920, charging may stop within anysuitable time period such as, for example, approximately 1 ms (could bemore or less than 1 ms) and the rover may move after verifying the bitsetting in the register and upon instruction from the control server.After charging has been disabled and the rover may leave the charginglocation with no risk of arcing on loss of pad contact or bounce.

FIG. 10 is a schematic illustration of a control system 1000 forcontrolling an autonomous rover charging system in accordance withaspects of the disclosed embodiment. The control system 1000 includescharger monitor software 1010 which according to some aspects, mayreside in a memory of control server 120. According to other aspects,the charger monitor software 1010 may reside in a memory of anautonomous rover controller such as controllers 420, 530, 632 describedabove. It is noted that the controller/control server where the softwareresides includes suitable structure for executing the software such thatthe controller/control server is configured to perform or otherwiseexecute the software functions as described herein. The charging controlsystem 1000 may provide for monitoring of the state of each chargingstation, changing the state of each charging station individually undersoftware control, terminating operation of one or more charging suppliesand disconnecting power to one or more sets of charging pads to allowmaintenance access to a charging location. In this example, the chargingstations 1020A-1020E, 1021A-1021E, 1022A-1022E, 1023A-1023B are disposedat respective lift 1050A, 1050B, 1050C, 1050D locations, where the lifts1050A, 1050B, 1050C, 1050D are substantially similar to one or more oflifts 150A, 150B described above. In this aspect a single or commoncontrol system 1000 is illustrated for the charging stations1020A-1020E, 1021A-1021E, 1022A-1022E, 1023A-1023B but in other aspectsthere may be more than one control system (similar to control system1000) where each control system is connected to any suitable number ofcharging stations. For example, charging stations 1020A-1020E and1021A-1021E may be connected to a common control system while chargingstations 1022A-1022E are connected to a separate control system andcharging stations 1023A-1023E are connected to yet another controlsystem.

As described above, a group of charging supplies, for example, incharging stations 220 and 300 each have a communications port 222 and310, respectively, for communication with the network 180.

The control system may also include a System Health Monitoring Function(HMF) as part of the charger monitor software 1010. The HMF maycorrelate information from the various autonomous rovers, chargingsupplies, and charging locations to determine the status of variouscomponents of the charging system. As an example only, a charging supplymay be visited by some number of rovers, each rover will visit somenumber of charging supplies, and a set of charging pads will be used bysome number of rovers. Synthesizing this information along with anyother suitable information, for example, a level of charge for eachrover, may enable, for example, identification of charging supplies inneed of maintenance or calibration, a precise determination of acapacitance for each rover, tracking of degradation or anomalies of thecharging system for accurate charging decisions, precise statisticalestimates of an average energy per assigned task for each rover,comparison of charging contactor properties, effective maintenance ofthe system, preemptive identification of rovers in need of maintenance,and any other suitable task.

The HMF may include continuous monitoring of one or more autonomousrovers 110. An autonomous rover 110 may utilize the communicationinterface to provide various operational parameters to the HMF such as,for example, time stamped power source voltage levels, allowing the HMFto determine an average energy consumption of the rover 110. Each rover110 may continuously monitor its power source voltage while charging,for example, at any suitable time interval such as approximately atleast 2 times per second and may disable charging and raise a warning(e.g. sends any suitable message to any suitable controller such assystem/control server 120) if the power source voltage exceeds apredetermined value. If several rovers 110 raise the same warning forthe same charging station, that station may need calibration or othermaintenance. While an autonomous rover might still be able to use thatcharging station because of an ability of the rover to detectovervoltage the charger monitor software 1010 may cause the chargingstation to be disabled.

The HMF may also provide a continuous monitoring function to the chargermonitor software 1010. For example, the HMF may continuously apprise thecharger monitor software 1010 of the health of the charging system andallow for intelligent decisions regarding when to enable or disablechargers to minimize potentially damaging situations. The HMF maycollect and report health information for each charging station thatincludes charger timeouts, trips and over temperature. If, for example,over temperature or trip events exceed some predetermined number at acharging location within a predetermined time period, then the chargermonitor software 1010 HMF may disable charging at that location. The HMFmay periodically fetch and report any suitable error and warning wordsfrom the charging stations, supplies, and modules. The charger monitorsoftware 1010 response to these error and warning words may includeinstructing charging modules to automatically disable outputs if one ormore conditions are detected. During normal operations the chargermonitor software 1010 generally enables charging supply outputs.

The charger monitor software may also determine a minimum time forrovers to charge. For example, in one aspect the charger monitorsoftware 1010 may give every rover a minimum time to charge based uponan average charge time/job multiplied by some predetermined factor. Sucha charging scheme may have rovers fully charged to any suitablepredetermined working voltage such as, for example, approximately 46V,be tolerant of dead power supplies, and substantially eliminate use ofthe incomplete charge mode. In another aspect, the charger monitorsoftware 1010 may compute how much charge time is needed for the roverbased upon, for example, at least one or more of capacitance and voltagelevels and routing information.

Turning to FIGS. 11 and 12 , a remote charging unit 1210 may be providedto charge at least one autonomous rover 110 requiring a charge andunable to reach a charging location. The remote charging unit 1210 maybe sized and shaped so as to be transportable by maintenance personnelor another autonomous rover. In one aspect the remote charging unit 1210may take the form of a backpack, a carry case or have any other suitabletransportable configuration. In another aspect the remote charging unitmay be a transportable unit that can be mounted to or otherwise affixedto another autonomous rover 1310 (FIG. 12 ) for transport through thestorage and retrieval system.

The remote charging unit may include any suitable energy storage unit1212 such as a battery or capacitor. The energy storage unit may berechargeable so that the remote charging unit 1210 may be reusable. Theremote charging unit may include any suitable controls 1214. Forexample, the controls may provide for an operator to start and stop acharge and/or automatic start and stop of a charge upon, e.g., detectionthat the remote charging unit is coupled to the autonomous rover in needof charge. The remote charging unit may also include one or moreconnectors 1216 for transferring energy from the energy storage unit1212 to an onboard energy source of the at least one rover requiring acharge. Where two connections 1216 are provided simultaneous charging ofrovers may be performed. In one aspect a rover requiring a charge mayinclude a plug or other suitable connector 1218 in which the remotecharging unit connector 1216 interfaces for the transfer of energy. Inother aspects, such as when the remote charging unit 1210 is carried byanother rover 1310, the remote charging unit may include a probe 1220that interfaces with the connector 1218 of the rover requiring a chargesuch that when rovers 110 and 1310 are disposed adjacent one another theprobe is aligned with the receptacle (FIG. 12 ). The remote chargingunit 1210 may be used to charge one or more rovers (e.g. individually orsimultaneously) at any location within the storage and retrievalstructure or outside the storage and retrieval structure.

In accordance with one or more aspects of the disclosed embodiment, acharging system for an autonomous rover includes a charging interfacewith contacts that interface with the autonomous rover, a rover powersource for the autonomous rover, and circuitry operated by theautonomous rover for controlling charging of the rover power source.

In accordance with one or more aspects of the disclosed embodiment, anoutput of the charging interface is enabled when the rover accesses andde-accesses the contacts.

In accordance with one or more aspects of the disclosed embodiment, thecharging system includes one or more charging stations each of whichincludes the charging interface and rover entry to a charging station isdecoupled or independent from a charging station status.

In accordance with one or more aspects of the disclosed embodiment, thecharging system includes a charging supply connected to the charginginterface, the charging supply being configured to switch between one ormore of a constant current output mode, a constant voltage output mode,or a constant power output mode and switching between different outputmodes may be effected by one or more of automatically by the chargingsupply and by commands received from the circuitry operated by theautonomous rover.

In accordance with one or more aspects of the disclosed embodiment, thecircuitry operated by the autonomous rover is configured to control anoutput of the charging interface to effect charging of the rover powersource independent of a charging interface status when the autonomousrover accesses and de-accesses the contacts.

In accordance with one or more aspects of the disclosed embodiment, thecharging interface is disposed at a charging location and the circuitryoperated by the autonomous rover is configured to cause an output of thecharging interface to change between a safe and unsafe state to effect ahot swap entry and departure of the autonomous rover with respect to thecharging location.

In accordance with one or more aspects of the disclosed embodiment, thecharging system for an autonomous rover is part of a storage andretrieval system.

In accordance with one or more aspects of the disclosed embodiment, acharging system for an autonomous rover includes one or more chargingstations configured to engage the autonomous rover, each of the chargingstations comprising a charging supply; and a power source for theautonomous rover, wherein autonomous rover entry to a charging stationis decoupled or independent from a charging station status.

In accordance with one or more aspects of the disclosed embodiment, anoutput of the charging supply is enabled when the rover accesses andde-accesses a respective charging station.

In accordance with one or more aspects of the disclosed embodiment, thecharging supply is configured to switch between one or more of aconstant current output mode, a constant voltage output mode, and aconstant power output mode.

In accordance with one or more aspects of the disclosed embodiment,switching between different output modes may be effected by one or moreof automatically by the charging supply and by commands received fromthe circuitry operated by the autonomous rover.

In accordance with one or more aspects of the disclosed embodiment, thecharging system further includes circuitry on-board and operated by theautonomous rover, the circuitry being configured to control an output ofthe one or more charging stations to effect charging of the power sourceindependent of a charging station status when the autonomous roveraccesses and de-accesses the contacts.

In accordance with one or more aspects of the disclosed embodiment, acharging system for an autonomous rover includes a charging stationhaving contacts configured to engage the autonomous rover, a powersource for the autonomous rover, and circuitry operated by theautonomous rover the circuitry being configured to cause an output ofthe charging station to change between a safe and unsafe state to effecta hot swap entry and departure of the autonomous rover with respect tothe charging station.

In accordance with one or more aspects of the disclosed embodiment, anoutput of the charging station is enabled when the rover accesses andde-accesses the contacts.

In accordance with one or more aspects of the disclosed embodiment, thecharging supply is configured to switch between one or more of aconstant current output mode, a constant voltage output mode, and aconstant power output mode.

In accordance with one or more aspects of the disclosed embodiment,switching between different output modes may be effected by one or moreof automatically by the charging supply and by commands received fromthe circuitry operated by the autonomous rover.

In accordance with one or more aspects of the disclosed embodiment, acharging system for an autonomous rover includes a system controller anda charging station with one or more charging interfaces configured toengage the autonomous rover for charging, wherein entry to the chargingstation is under control of the autonomous rover and independent of thesystem controller.

In accordance with one or more aspects of the disclosed embodiment, anoutput of the charging interface is energized when the autonomous roveraccesses and de-accesses the contacts.

In accordance with one or more aspects of the disclosed embodiment,entry to the charging station is independent of communication betweenthe autonomous rover and the system controller.

It should be understood that the foregoing description is onlyillustrative of the aspects of the disclosed embodiment. Variousalternatives and modifications can be devised by those skilled in theart without departing from the aspects of the disclosed embodiment.Accordingly, the aspects of the disclosed embodiment are intended toembrace all such alternatives, modifications and variances that fallwithin the scope of the appended claims. Further, the mere fact thatdifferent features are recited in mutually different dependent orindependent claims does not indicate that a combination of thesefeatures cannot be advantageously used, such a combination remainingwithin the scope of the aspects of the invention.

What is claimed is:
 1. A charging system for a storage and retrievalsystem autonomous rover of a storage and retrieval system, where thestorage and retrieval system includes travel surfaces on which thestorage and retrieval system autonomous rover travels and storage spacesto and from which the storage and retrieval system autonomous rovertransfers storage consumer products, the charging system comprises: oneor more charging stations disposed adjacent the travel surfaces andconfigured to engage the storage and retrieval system autonomous rovertravelling on the travel surface for transport of the storage consumerproducts, each of the charging stations comprising a charging supply;and a power source for the autonomous rover; wherein autonomous roverentry to a charging station and control of an output of the one or morecharging stations by the storage and retrieval system autonomous roveris disunited and independent from a predetermined charging stationoutput energization status existing when the autonomous rover accessesthe charging station so that there is no charging control loop betweenthe storage and retrieval system autonomous rover and the one or morecharging stations and the predetermined charging station outputenergization status remains upon access of the autonomous rover to thecharging station and through charging of the autonomous rover.
 2. Thecharging system of claim 1, wherein an output of the charging supply isenabled when the rover accesses and de-accesses a respective chargingstation.
 3. The charging system of claim 1, wherein the charging supplyis configured to switch between one or more of a constant current outputmode, a constant voltage output mode, and a constant power output mode.4. The charging system of claim 3, wherein switching between differentoutput modes is automatically effected by one or more of the chargingsupply and by commands received from the circuitry operated by theautonomous rover.
 5. The charging system of claim 1, further comprisingcircuitry on-board and operated by the storage and retrieval systemautonomous rover, the circuitry being configured to turn charging of theautonomous rover on and off disunited and independent of the chargingstation output energization status when the autonomous rover accessesand de-accesses the contacts.
 6. The charging system of claim 1, whereineach of the one or more charging stations includes at least one chargingpad, and each charging pad of the at least one charging pad of arespective charging station is disposed in a floor on which the storageand retrieval system autonomous rover travels, the at least one chargingpad being configured to interface with an autonomous rover charging padthat is mounted to an underside of the autonomous rover and faces thefloor.
 7. A charging system for an autonomous rover, the charging systemcomprises: a charging station having contacts configured to engage theautonomous rover; a power source for the autonomous rover; and circuitryoperated by the autonomous rover, the circuitry being configured tocause an output of the charging station to change between a safe andunsafe state to effect a hot swap entry and departure of the autonomousrover with respect to the charging station.
 8. The charging system ofclaim 7, wherein an output of the charging station is enabled when therover accesses and de-accesses the contacts.
 9. The charging system ofclaim 7, wherein the charging supply is configured to switch between oneor more of a constant current output mode, a constant voltage outputmode, and a constant power output mode.
 10. The charging system of claim9, wherein switching between different output modes may be effected byone or more of automatically by the charging supply and by commandsreceived from the circuitry operated by the autonomous rover.
 11. Acharging system for an autonomous rover, the charging system comprises:a system controller; and a charging station with one or more charginginterfaces configured to engage the autonomous rover for charging;wherein entry to the charging station is under control of the autonomousrover and independent of the system controller.
 12. The charging systemof claim 11, wherein an output of the charging interface is energizedwhen the autonomous rover accesses and de-accesses the contacts.
 13. Thecharging system of claim 11, wherein entry to the charging station isindependent of communication between the autonomous rover and the systemcontroller.
 14. A charging system for a storage and retrieval systemautonomous rover, the charging system comprising: a system controller;and a charging station with one or more charging interfaces configuredto engage the storage and retrieval system autonomous rover forcharging; wherein the charging station is configured so that the storageand retrieval system autonomous rover independently controls both anoutput and a mode of charging of the charging station after autonomousrover contact is made with the one or more charging interfaces, andwhere an energization of contacts of the one or more charging interfacesat autonomous rover entry to the charging station is disunited from apredetermined charging station output energization status existing whenthe autonomous rover accesses the charging station and the predeterminedcharging station output energization status remains upon access of theautonomous rover to the charging station and through charging of theautonomous rover.
 15. The charging system of claim 14, wherein an outputof the charging interface is energized when the autonomous roveraccesses and de-accesses contacts of the one or more charginginterfaces.
 16. The charging system of claim 14, wherein entry to thecharging station is independent of communication between the autonomousrover and the system controller.
 17. A method for charging a storage andretrieval system autonomous rover, the method comprising: providing acharging station with one or more charging interfaces configured toengage the storage and retrieval system autonomous rover for charging;independently controlling, with the storage and retrieval systemautonomous rover, both an output of the charging station and a mode ofcharging the storage and retrieval system autonomous rover by thecharging station, after autonomous rover contact is made with the one ormore charging interfaces, and where an energization of contacts of theone or more charging interfaces at autonomous rover entry to thecharging station is disunited from a predetermined charging stationoutput energization status existing when the autonomous rover accessesthe charging station and the predetermined charging station outputenergization status remains upon access of the autonomous rover to thecharging station and through charging of the autonomous rover.
 18. Themethod of claim 17, wherein an output of the charging interface isenergized when the storage and retrieval system autonomous roveraccesses and de-accesses contacts of the one or more charginginterfaces.
 19. The method of claim 17, wherein entry to the chargingstation is independent of communication between the autonomous rover anda charging system controller.